Gripping member for well tools or the like

ABSTRACT

The improved gripping member disclosed herein includes a unitary body arranged to encircle a portion of the well tool and having upper and lower ends and a wall engaging portion located adjacent the upper and lower ends. The wall engaging portions are disposed on relatively opposite sides of the unitary body. The gripping member is arranged to move on the well tool from a retracted position wherein the wall engaging portions are out of engagement with the wall and a holding position wherein the wall engaging portions are in engagement with the wall. Means, for example a pair of bow springs are disposed on the unitary body on opposite sides thereof and at a generally normal position relative to the location of the wall engaging portions. The bow springs are arranged to extend into frictional engagement with the wall of the well bore to resist movement of the gripping member therethrough so that other portions of the well tool can be moved relatively to the gripping member when desired.

United States Patent [i9] Fisher, Jr. et al.

[ GRIPPING MEMBER FOR WELL TOOLS OR THE LIKE [75] Inventors: Ernest Pillow Fisher, Jr., Carrollton;

David Lewis Abney, Jr., Stafford, both of Tex.

[73] Assignee: Dresser Industries, Inc., Dallas, Tex.

[22] Filed: Jan. 2, 1973 [21] Appl. No.: 320,022

[52] US. Cl. 166/216, 166/134 [51] Int. Cl E2lb 23/00 [58] Field of Search..... 166/206, 216, 217, 134

[56] References Cited UNITED STATES PATENTS 3,664,417 9/1970 Conrad 166/216 3,548,936 12/1970 Kilgore 166/217 Primary Examiner.lames A. Leppink Attorney, Agent, or Firm-John N. l-lazelwood; William E. Johnson, Jr.; Michael J. Caddell Apr. 16, 1974 [5 7] ABSTRACT The improved gripping member disclosed herein in cludes a unitary body arranged to encircle a portion of the well tool and having upper and lower ends and a wall engaging portion located adjacent the upper and lower ends. The wall engaging portions are disposed on relatively opposite sides of the unitary body. The gripping member is arranged to move on the well tool from a retracted position wherein the wall engaging portions are out of engagement with the wall and a holding position wherein the wall engaging portions are in engagement with the wall. Means, for example a pair of how springs are disposed on the unitary body on opposite sides thereof and at a generally normal position relative to the location of the wall engaging portions. The bow springs are arranged to extend into frictional engagement with the wall of the well bore to -resist movement of the gripping member therethrough so that other portions of the well tool can be moved relatively to the gripping member when desired.

6 Claims, 3 Drawing Figures GRIPPING MEMBER FOR WELL TOOLS OR THE LIKE BACKGROUND OF THE INVENTION This invention relates generally to improved gripping members for well tools or the like. More particularly, but not by way of limitation, this invention relates to an improved unitary type gripping member having drag members or the like integrally located thereon.

U.S. Pat. No. 3,548,936, issued Dec. 22, l970, to M. D. Kilgore, et al., illustrates a number of packer embodiments incorporating unitary gripping members. That patent also clearly discloses the function and operation of the unitary gripping member.

As will be apparent to those skilledin the art of well tools, it is necessary to downhole tools to provide some means for providing relative movement between various parts of the tool while the tool is disposed in the well bore. One means utilized in the past for providing such relative movement has been to utilize either drag springs or drag blocks which are resiliently biased outwardly into engagement with the casing. Several variations of the drag spring/drag block arrangement are shown in the above-mentioned U.S. patent. Such drag springs or drag blocks have usually been carried in a body mounted on the well tool that is releasable when it is desired to cause the relative movement of the parts, such as during the setting of the well tool in the well bore. Providing such drag blocks and drag springs on a separate body not only increases the cost of the manufacture of the well tool, but also increases the length and weight of the tool.

Accordingly, it is one object of this invention to provide an improved gripping member having the drag member mounted directly on the gripping member.

Another object of the invention is to provide an improved gripping member for well tools which permits the overall cost of the tool to be reduced by the use of the improved gripping member having drag members thereon.

Still another object of the invention is to provide an improved gripping member which permits the overall weight and size of the tool to be reduced by the use of the gripping member having drag members thereon.

SUMMARY OF THE INVENTION The improved gripping member of this invention includes: a unitary body member having top and bottom ends and having a casing engaging portion located adjcent each of the top and bottom ends. The casing engaging members are located on relatively opposite sides of the unitary body member. The improved gripping member also includes a drag member located on each side of the unitary body member and mounted thereon and arranged to extend outwardly into engagement with the wall of the well bore. The drag members are constructed in such a manner that they are resiliently urged outwardly into frictional engagement with the wall of the well bore.

The foregoing and additional objects and advantages of the invention will become more apparent as the following detailed description is read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view, partly in elevation and partly in cross-section, illustrating a packer having a gripping member thereon that is constructed in accordance with the invention.

FIG. 2 is a view of a portion of FIG. 1 showing the components thereof in another operating position.

FIG. 3 is a transverse cross-sectional view of a portion of FIG. 2 taken generally along the line 3--3 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing and to FIG. 1 in particular, shown therein and generally designated by the reference character 10 is a well packer incorporating gripping means that is constructed in accordance with the invention. The well packer 10 is illustrated as being disposed in a casing 12 that is located in a well bore (not shown).

The well packer 10 includes a tubular body or mandrel 14 that is threadedly connected at its upper end with an adaptor 16 that provides a downwardly facing shoulder or abutment 18. The adaptor 16 is threadedly connected with a conduit or running-in string 20 that extends to the surface of the well bore. The conduit 20 is utilized for the purpose of moving the well packer 10 through the well bore.

The tubular body 14 and packer 10 has a longitudinal or axial centerline 22 that is coincident with the centerline of the casingl2 when the packer 10 is concentrically disposed therein. The tubular body 14 includes a portion 24 of reduced diameter forming a downwardly facing, exterior flange 26'for purposes that will be explained hereinafter. It will be noted that the reduced diameter portion 24 extends through a flange or abutment member 27 which is slidingly positioned thereon.

The abutment member 27 provides an upwardly facing surface 28 and a downwardly facing surface 30 that is in engagement with deformable packing 32. The lower end of the packing 32 is in engagement with an abutment 34 that is attached to the tubular body 14 by one or more shear screws 35. It will be appreciated that movement of the abutment member 27 and the abutment 34 relatively together will deform the packing 32 into sealing engagement with the casing 12 and with the tubular body 14 in a manner well known in the well packer art.

Encircling the tubular body 14, just below the downwardly facing shoulder 18, is a gripping member 36 that is arranged for both sliding and pivoting movement with respect to the tubular body 14. To provide such movement, the exterior of the tubular body 14 is provided with a pair diametrically opposed slots 38 and 40 (see FIG. 3). Pivot means 42 carried by the gripping member 36 are located in the slots 38 and 40 and will be described in more detail hereinafter.

The gripping member 36 illustrated includes an upper end 44 and a lower end 46 that are angularly disposed with respect to each other. The upper end 44 includes a contact portion 48 that is offset from the pivot axis of the gripping member 36 in a direction to cause the gripping member 36 to rotate toward the retracted position illustrated in FIG. 1 when in engagement with the downwardly facing shoulder 18.

The lower end 46 on the gripping member 36 includes a contact portion 50 that is offset from the pivot axis of the gripping member 36 in the same direction as was contact portion 48. It can be seen that engagement of the contact portion 50 will cause the gripping member 36 to pivot toward the casing engaging portion illustrated in FIG. 2.

The gripping member 36 also includes an upper gripping portion 52 and a lower gripping portion 54 disposed adjacent the upper and lower ends 44 and 46 respectively. The gripping portions 52 and 54 are preferably provided with teeth to enhance their frictional engagement with the casing 12.

The gripping member 36 is relieved from the bottom end 46, providing a downwardly facing shoulder 56 thereon. Similarly, the gripping member 36 is relieved from the upper end 44 providing an opening 59 through which a leaf-type spring 60 extends. The spring 60 has one end that is attached to the gripping member 36 and the other end frictionally engaging the tubular body 14 resiliently urging the gripping member 36 toward the retracted position shown in FIG. 1.

Encircling the tubular body 14 between the gripping member 36 and the movable abutment member 27 is an articulated head 62. The articulated head 62 includes a top end 64 and a bottom end 66. The top end 64 includes a contact portion 68 that is engagable with the contact portion 50 on the lower end 46 of the gripping member 36. The bottom end 66 of the head 62 includes an arcuate contact portion 70 configured in such a manner that the contact portion 70 engages the movable abutment member 27 along a line extending through and disposed normally to the centerline 22.

The head 62 also includes an upper casing engaging portion 72 located adjacent to the top contact portion 68 and a lower casing engaging portion 74 located adjacent to the bottom end 66 and on the relatively opposite side of the head 62 from the contact portion 72. The head 62 has been counterbored from the top end 64 providing an upwardly facing shoulder 76, which when in the retracted position, is in engagement with the downwardly facing flange 26 on the tubular body 14 to aide in retaining the head 62 in the retracted position shown in FIG. 1 as the well packer is lowered into the well bore.

A slot 78 extends from the top end 64 of the head 62 and is sized to receive a lug 80 which is welded to or otherwise secured to the tubular body 14. The lug 80, in cooperation with the slot 78, aides in maintaining the head 62 in alignment with the gripping member 36 so that the contact portions 50 and 68 will be in the proper position for engagement during the operation of the well packer 10. The lug 80 also functions during the retrieval of the well packer 10 to engage the downwardly facing shoulder 56 in the gripping member 36 to move the gripping member 36 from the set or casing engaging position to the retracted position.

It is necessary in the operation of the well packer 10 to provide some means for affording relative movement between various parts of the packer 10. The transverse cross-section of FIG. 3 illustrates the structure of drag springs 82, which are directly mounted on the gripping member 36 and are resiliently biased into frictional engagement with the casing 12.

As can be seen therein, the pivot means 42 includes a pair of pivot bushings or members 84 that extend through the wall of the gripping member 36 and project into the slots 38 and 40 formed in the tubular body 14. The bushings 84 are each counterbored to receive a coil spring 86 which encircles stem 88 of pins 90. Each of the pins 90 has an enlarged head 92 that engages one end of the springs 86 while the other end of the springs 86 is in engagement with the bushings 84. The arrangement is such that the springs 86 bias the pins 90 outwardly against the interior of the drag springs 82. If the OPERATION OF THE PREFERRED EMBODIMENT With the conduit 20 connected to the packer 10, the packer 10 is lowered into the casing 12 until the packer 10 reaches the desired location in the well bore. As the packer 10 moves downwardly, the drag springs 82 are in frictional engagement with the casing 12 so that the gripping member 36 rides upwardly in the slots 38 and 40 engaging the upper end 44 of the gripping member 36 in with the shoulder 18. Such engagement, plus the action of the spring 60, retains the gripping member 36 in the retracted position.

It should also be noted that the upwardly facing annular shoulder 76 on the articulated head 62 will remain in engagement with the downwardly facing shoulder 26 on the tubular body 14. With the shoulders 26 and 76 in engagement, the articulated head 62 remains in the retracted position illustrated in FIG. 1.

After the packer 10 has reached the desired position in the casing 12, the conduit 20 is raised pulling the tubular body 14 upwardly therewith. Due to the frictional engagement of the drag springs 82 with the casing 12, the gripping member 36 remains in a relatively fixed position. The upward movement of the tubular body 14 carries the lower abutment 34 upwardly, raising the packer 32, the movable abutment member 27, and the articulated head 62 therewith toward the relatively fixed gripping member 36.

Continued upward movement of the tubular body 14 brings the contact portion 68 on the upper end 64 of the head 62 into engagement with the contact portion 50 on the lower end 46 of the gripping member 36. When this occurs, the gripping member 36 is pivoted about the pivot means 42 until the casing engaging por tions 52 and 54 thereon frictionally engage the casing 12 locking the gripping member 36 in the casing 12.

Simultaneously, the articulated head 62 rotates or pivots on the tubular body 14 until the casing engaging portions 72 and 74 thereon are in engagement with the casing 12 as illustrated in FIG. 2. The lower contact portion of the articulated head 62 is in engagement with the movable abutment member 27 along a line that extends through and normal to the axial centerline 22 of the tubular body 14.

From the foregoing, it can be seen that the gripping member 36 due to the location of the casing engaging portions 52 and 54 thereon and the offset location of the contact portion 68 on the lower end 46 will normally have a tendency to exert an eccentric load on anything engaging the contact portion 68. To compensate for this, the articulated head 62 is pivoted in an opposite direction to the pivotal direction of the gripping member 36 and engages the casing through casing engaging portions 72 and 74 to transfer the lateral component of the eccentric loading force into the casing 12 thereby counteracting any moment that the gripping member 36 may impose. Further, the arrangement of the contact portion 70 on the head 62 prevents the imposition of any, other than a load parallel to the centerline 22 from being imposed upon the movable abutment member 27. Thus, the packer will remain substantially concentric with the casing 12 during the imposition of setting forces on the packer 10.-

After the gripping member 36 has been set, additional upward movement of the tubular body 14 moves the fixed abutment 34 relatively toward the movable abutment member 27 deforming the packing 32 therebetween. The packing 32, under the force imposed by the fixed abutment 34, deforms into fluid-tight sealing engagement with the tubular body 14 and with the easing 12.

To remove the packer 10 from the well bore, additional upward force is imposed upon the conduit and tubular body 14 until the shear screws 35 part permitting the tubular body 14 to move upwardly relative to the gripping member 36. The upward movement of the tubular body 14 continues until the lug 80 thereon engages the downwardly facing shoulder 56 on the gripping member 36. This engagement forces the gripping member 36 to rotate from the set position illustrated in FIG. 2 to the retracted position illustrated in FIG. 1.

After the gripping member 36 has been released, the head 62 is returned to its retracted position and the movable abutment member 27 moves relative to the fixed abutment 34 permitting the packing 32 to return to its undeformed condition. After the foregoing has occurred, it is only necessary to continue raising the conduit 20 to remove the well packer 10 from the well bore.

From the foregoing, it should be apparent that a well packer constructed in accordance with this invention includes a unitary gripping member and means associated therewith that prevents the imposition of a mowith this invention avoid the nonconcentric location of the packer, but it also avoids the imposition of eccentric loads on moving parts of the packer which could and, have in the past, occasionally resulted in the jamming of the moving parts.

As will be apparent from the foregoing, the provision of the drag means directly on the gripping member avoids the necessity for providing a separate drag body. The elimination of the separate drag body permits the packer to be reduced in length and complexity with the attendant reduction in size, weight, and cost.

It will be understood that the embodiment described in detail hereinbefore is presented by way of example only and that many changes and modifications can be made thereto without departing from the spirit and scope of the invention.

10 a bore extending through said gripping member intersecting said ends for receiving a portion of the well tool;

a plurality of gripping teeth adjacent each end of and located on generally opposite sides of said gripping 15 member, the distance between said toothed portions being greater than the diameter of the well bore whereby said toothed portions can engage the well bore wall; and

a portion intermediate said ends having a dimension less than the diameter of the well bore, whereby the well tool can move through the well bore; and,

friction means on said gripping member for engaging the well bore wall, whereby the well tool can be moved telescopically through said gripping member.

2. The gripping apparatus of claim 1 wherein said means for frictionally engaging the well bore wall includes at least a pair of members resiliently biased relatively outwardly with respect to said body member toward the well bore.

3. The gripping apparatus of claim 1 wherein said means for frictionally engaging the well bore wall includes:

at least a pair of outwardly-bowed, leaf springs; a pin having an enlarged head engaging each said leaf spring; and,

a coil spring for each said leaf spring encircling each said pin and having one end engaging said body member and another end engaging the heads of said pins resiliently biasing said leaf springs relatively outwardly toward the well bore wall.

4. The gripping apparatus of claim 1 and also including:

a pair of aligned holes extending through the wall of said body member at approximately 90 relative to v the location of said wall engaging portions; and,

a pivot member positioned in each of said holes and projecting into said bore forming a pivot axis for said body member.

5. The gripping apparatus of claim 5 wherein:

said pivot members include a bore extending partially therethrough from the exterior of said body member; and,

said means for frictionally engaging the well bore wall includes an outwardly bowed, leaf spring overlying each said pivot member, and

mean engaging said pivot members and said leaf 5 gaging the head portion of said pins resiliently urging said pins outwardly into engagement with said leaf springs. 

1. Gripping apparatus arranged to be moveably mounted on a well tool and arranged to engage a well bore wall or the like to hold the well tool in the well bore, said apparatus comprising: a unitary tubular gripping member having first and second ends, said gripping member being pivotally mounted on said well tool; a bore extending through said gripping member intersecting said ends for receiving a portion of the well tool; a plurality of gripping teeth adjacent each end of and located on generally opposite sides of said gripping member, the distance between said toothed portions being greater than the diameter of the well bore whereby said toothed portions can engage the well bore wall; and a portion intermediate said ends having a dimension less than the diameter of the well bore, whereby the well tool can move through the well bore; and, friction means on said gripping member for engaging the well bore wall, whereby the well tool can be moved telescopically through said gripping member.
 2. The gripping apparatus of claim 1 wherein said means for frictionally engaging the well bore wall includes at least a pair of members resiliently biased relatively outwardly with respect to said body member toward the well bore.
 3. The gripping apparatus of claim 1 wherein said means for frictionally engaging the well bore wall includes: at least a pair of outwardly-bowed, leaf springs; a pin having an enlarged head engaging each said leaf spring; and, a coil spring for each said leaf spring encircling each said pin and having one end engaging said body member and another end engaging the heads of said pins resiliently biasing said leaf springs relatively outwardly toward the well bore wall.
 4. The gripping apparatus of claim 1 and also including: a pair of aligned holes extending through the wall of said body member at approximately 90* relative to the location of said wall engaging portions; and, a pivot member positioned in each of said holes and projecting into said bore foRming a pivot axis for said body member.
 5. The gripping apparatus of claim 5 wherein: said pivot members include a bore extending partially therethrough from the exterior of said body member; and, said means for frictionally engaging the well bore wall includes an outwardly bowed, leaf spring overlying each said pivot member, and mean engaging said pivot members and said leaf springs for resiliently biasing said leaf springs toward the well bore wall.
 6. The gripping apparatus of claim 5 wherein said means engaging said pivot members and leaf springs includes: a pin disposed in the bore of each said pivot member and having a head portion in engagement with said leaf springs; and, a coil spring encircling each said pin having one end engaging said pivot members and another end engaging the head portion of said pins resiliently urging said pins outwardly into engagement with said leaf springs. 